You can check your CP version by running the following command on your CP as root:
rpm -qa | grep onapp-cp
This will give you the version you're running, as shown in this example:
onapp-cp-vnc_proxy-3.0.0-4.el5 onapp-cp-3.2.2-25 onapp-cp-install-3.2-9
You can also use the API request to check the version of your cloud installation.